Adjustable resilient writing instrument



Sept. 20, 1966 R. THURMAN ETAL 3,

ADJUSTABLE RESILIENT WRITING INSTRUMENT 2 Sheets-Sheet 1 Filed Sept. 18, 1963 INVENTORS RICHARD L THLJF-?N\AN BY AUGUST J. COUTRE'. MK?

ATTY.

Sept. 20, 1966 R, THURMAN ETAL 3,273,541

ADJUSTABLE RESILIENT WRITING INSTRUMENT 2 Sheets-Sheet 2 Filed Sept. 18, 1965 INVENTORS RICHARD L.TI-IU I ZMAN AUGU ST J. COU TD E m Q q a I a 2 8 M M NW N v 7 M & W 7 QM 6 G r k R a 3 I Y \Y H HI I I I II I I 0 III m S M I I P .I III IF... III

United States Patent Office Patented Sept. 20, 1966 3,273,541 ADJUSTABLE RESILHENT WRITING INSTRUMENT Richard L. Thurman, Beioit, and August J. Contre,

.lanesville, Wis, assignors to The Parker lPen Qumpany, .lanesriiie, Win, a corporation of Wisconsin Filed 113, 1963, Ser. No. 399,723 9 Claims. (Cl. Mil-42.03)

The present invention relates to writing instruments of the type in which the writing unit is adapted to yield reciprocably under writing pressure against the influence of a spring or other resilient member, a principal object of the invention being to incorporate this feature of a resilient writing tip in a writing instrument of the propel-repel or retractile point type.

Another object of the invention is to provide such a writing instrument with means for readily adjusting the resiliency of the writing tip to a selected degree of firmness or to a condition in which the tip is completely nonyielding under writing pressure.

Still another object of the invention is to provide a simple, economical and reliable mechanism for accomplishing the foregoing objects in a writing instrument of a conventional retractile type adapted to use standard interchangeable writing units.

These and other important objects of the invention will appear from the following description, reference being made to the accompanying drawings in which:

FIG. 1 is a longitudinal view of a Writing instrument according to a preferred embodiment of the invention showing the barrel, cap and internal members in section, the writing unit or ball point cartridge in elevation and the push button actuating member partially in section;

FIG. 2 is an elevational view of the plunger member shown in section in FIG. 1;

FIG. 3 is a top elevational view of the detent adjusting member shown in section in FIG. 1;

FIG. 4 is a top elevational view of the tubular detent member shown in section in FIG. 1;

FIGS. 5 through 8 are diagrammatic developed Views illustrating step-by-step in the manner in which the camming surfaces of the ratchet member are engaged alternately by stationary actuating means to effect projection and retraction of the writing element; and

FIG. 9 is a fragmentary longitudinal sectional view of an alternate embodiment of the invention.

Referring now to the drawings, the preferred embodiment of the invention shown in FIGS. 14 comprises a housing 11 having a forward section 12 with a tapered tip 13, and a rear section 14, which may be provided with a pocket clip (not shown). The housing 11 is formed with a bore defining a chamber 15 which receives the front end of the writing element 16 associated with a projection-retraction mechanism to be described hereinafter.

The writing element 16, which in the illustrated embodiments of the invention comprises a ball point cartridge, is hereinafter referred to as a cartridge. Such a cartridge includes an ink reservoir section 17 containing a quantity of ink suitable for use with ball point writing instruments, an ink feed section 18, and a ball writing point 19 carried at the forward end of the member 18 in communication with the ink in the reservoir section through an ink feed channel (not shown).

The forward portion 21 of chamber 15 is of reduced diameter for receiving a return or retracting spring 22, which is seated against a shoulder 23 and bears against the forward end of the reservoir section 17 to bias the cartridge rearwardly. The portion 24 of the bore ahead of shoulder 23 is of still smaller diameter to receive and guide the ink feed section 18 of the cartridge.

Secured rigidly in the rearward end of the reservoir section 17 and forming a unitary part of the cartridge is a ratchet member 25 which constitutes an essential part of the projection-retraction mechanism of the instrument. The ratchet member also serves as a plug for the rear end of the reservoir section, and is provided with a small central bore (not shown) to supply air to the reservoir section to fill the space left by the withdrawal of ink from the cartridge. It is obvious, however, that the invention is equally applicable to a construction in which the ratchet member is permanently mounted within the pen rather than being integral with the writing unit.

The ratchet member is rotatably and slidably supported by a tubular detent member 26 disposed within a surround.- ing detent adjusting member 27, which, in turn is connected by coarse threads 28 to a connector member 29 tightly and permanently fitted within the forward end of the rear section 14. In addition to locating the detent member, as hereinafter explained, the connector member also serves to join the rear section 14 with the removable front section 12 by means of threads 30..

As is most clearly shown in FIGS. 1 and 4, the tubular detent member 26 is provided with a pair of oppositely disposed detent ribs 31 and 32 which engage oppositely disposed rearwardly facing surfaces of the ratchet memher as described hereinafter to define the projected and retracted positions of the cartridge. These detent ribs, and a pair of corresponding inward projections 33 and 34 (FIG. 3) at the top end of detent adjusting member 27 are maintained in alignment with each other and with plunger 35 by slots 36 and 37 (FIGS. 1 and 2) in the plunger, which is reciprocable in the housing against the influence of plunger spring 38 by means of push button 39'. The uppermost position of the plunger is determined by a flange 41 on the push button, which engages an inwardly turned lip 42 of stop member 43, which in turn bears against an internal shoulder 44 in the rear section 14.

The tubular detent member 26 normally is maintained in contact with the rearward surface 45 of connector member 29 by the influence of spring 46, which is compressed between an internal shoulder 47 at the rearward end of the detent adjusting member 27 and an external shoulder 48 on the tubular detent member 26. Spring 46 is sufliciently strong to maintain the tubular detent member in contact with connector member 29 against the rearward thrust of spring 22 during the operations of projecting and retracting the cartridge.

The operation of the projection-retraction mechanism of the instrument can best be visualized by reference to FIGS. 5 through 8, which are diagrammatic developed views showing the various functional surfaces of the ratchet member, detent ribs, and plunger.

On the ratchet member, the rearwardly facing cam surfaces 50 and 51, and 52 and 53 are diametrically opposite one another respectively and are equidistantly spaced from the axis of the ratchet member throughout their entire extent. Each of these cam surfaces is approximately a 45-degree helix about the cylindrical body of the ratchet member. The cam surfaces are oriented in the same sense, i.e. they are oriented so as to impart a unidirectional movement to the ratchet member when moved against a rotationally fixed cam actuating means. Each of the diametrically opposite bottom surfaces 54 and 55 is located axially forward of the cam surfaces 50, 51, 52 and 53. A stop surface 56 extending substantially parallel to the axis of the cam body is disposed between the trailing edge of the bottom surface 54 and the leading edge of the cam surface 50, with a corresponding oppositely disposed stop surface 57 being located between the trailing edge of bottom surface 55 and the leading edge of cam surface 51. A second pair of similar oppositely located stop surfaces 59 and 61 are disposed respectively between the leading edges of cam surfaces 52 and 53 and the trailing edges of cam surfaces 51 and 50. The portions of the ratchet defined by cam surfaces 50 and 51 are each substantially twice as wide as each of those defined by cam surfaces 52 and 53 and by bottom surfaces 54 and 55.

As shown in FIG. 1, the cam surfaces of the ratchet surround a central hub 62 of such diameter as to fit slidably between actuating fingers 63 and 64 of plunger 35 and between detent ribs 31 and 32. Fingers 63 and 64 and the ratchet engaging ends of detent ribs 31 and 32 have the respective ends thereof formed at an angle corresponding to that of the ratchet carn surfaces engaged thereby.

The cartridge is biased rearwardly by the retracting spring 22 which serves to provide the motive power for effecting the axial retracting movement and also rotational movement of the ratchet by biasing opposite pairs of ratchet cam surfaces against the cam engaging surfaces of the plunger fingers and the detent ribs, depending on the angular orientation of the ratchet member with respect thereto. Although, as will be explained later, the actuating fingers and detent ribs may be rotated relative to the housing to adjust the resiliency of the writing tip, the frictional forces resisting such rotation of these elements are substantially greater than the frictional drag between the cartridge and spring 22, so that the carnming action between the ratchet and these elements results in rotation of the cartridge but not of the detent member and plunger. If the orientation of the ratchet member is such that the ends of the detent ribs engage the cam surfaces 50 and 51 (FIG. 7), the cartridge will be maintained in its projected position, while if the orientation is such that the ends of the detent ribs engage bottom surfaces 54 and 55 (FIG. the ratchet member and the cartridge will be permitted to assume a more rearward position in the housing to retract the writing point.

To illustrate the specific mode of operation of the projection-retraction mechanism, FIG. 5 shows the relative positions of the plunger fingers, detent ribs and ratchet member when the cartridge is in its retracted position with the bottom surfaces 54 and 55 urged into engagement with detent ribs 31 and 32 respectively by spring 22. When the push button is depressed, the actuating fingers 63 and 64 will be moved downwardly with respect to the stationary detent ribs and will carry with them the ratchet member. The interaction between the camming end portions of fingers 63 and 64 and the cam surfaces 56 and 51, respectively engaged thereby, will tend to rotate the ratchet member in a clockwise direction as viewed from the front of the pen or to the right in the developed view of FIG. 5. Initially, however, such rotational movement of the ratchet member will be prevented by the stop surfaces 56 and 57 which bear against the respective detent ribs 31 and 32.

When the ratchet member has been depressed to an extent suflicient to permit the stop surfaces 56 and 57 to clear the detent ribs 31 and 32, as shown in FIG. 6, the ratchet member is free to rotate under the influence of spring 22 until fingers 63 and 64 abut with longitudinally extending stop surfaces 61 and 59 respectively. When the push button 39 is released to allow the actuating fingers to be retracted by plunger spring 38, the ratchet member will be free to continue its rotational movement until detent ribs 31 and 32 abut the longitudinal stop surfaces 61 and 59 respectively as shown in FIG. 7. The cartridge Will thus have been rotated through an angle of 90 degrees and will be in its projected position.

When the push button is depressed again, the ends of the actuating fingers 63 and 64 engage cam surfaces 53 and 52 respectively and advance the ratchet member until the stop surfaces 61 and 59 are clear of the respective detent ribs 31 and 32, whereupon the ratchet will rotate as shown in FIG. 8, until stop surfaces 57 and 56 engage the respective fingers 63 and 64. In this position the detent ribs 31 and 32 are aligned respectively with cam surfaces 53 and 52 and, when the push button is then released and the plunger fingers withdrawn, the ratchet member will rotate until the ribs 31 and 32 engage stop surfaces 57 and 56, whereupon the ratchet and cartridge are returned to the retracted position with the ends of ribs 31 and 32 in engagement with the respective bottom surfaces 55 and 54. In this position, the illustrated elements are in the same relative positions shown in FIG. 5, except that the ratchet has been rotated degrees.

As previously explained, the tubular detent member 26 is maintained in its forward position defined by its engagement with connector member 29, by the influence of spring 46. Although spring 46 is of sufiicient strength to prevent the separation of the detent member and the connector member during the operations of projecting and retracting the cartridge, it is apparent by reference to FIG. 1, that the application of a rearward force to the cartridge in excess of that exerted by retracting spring 22, as results when the writing tip is pressed against a writing surface, will cause the cartridge to yield resiliently in a rearward direction relative to the instrument housing by displacing the detent member rearwardly against the influence of spring 46.

To enable the resiliency of the Writing tip to be adjusted to the preference of the user, or, if desired, to be eliminated entirely, the detent adjusting member 2 7, which provides the rearward abutment for spring 46, is axiallly adjustable to alter the compression of the spring. This adjustable feature is achieved in the embodiment shown in FIG. 1 by the threaded connection 28 between members 27 and 29, whereby the rotation of the detent adjusting member relative to the connector member varies the axial relation thereof between a forward position in which the coils of spring 46 are tightly compressed, thereby eliminating resiliency of the writing tip, and a rearward position in which the top surface 65 of member 27, engages the lower end 66 of stop member 43, in which position spring 46 is extended to provide maximum resiliency. In FIG. 1, the detent adjusting member 27 is shown in a position adjacent but not in contact with stop member 43, with spring 46 in a corresponding state of compression. Since the detent member 26 normally abuts against the rearward surface of the immovable connector, it will be observed that the adjustment of the resiliency of the writing tip does not alter the normal axial posi tion of the tip relative to the housing.

In the illustrated embodiment, the adjustment of resiliency is accomplished by rotating the push button 39 relative to the housing. As previously explained, the plunger 35, and members 26 and 27 are maintained in the same radial relation by the engagement of detent ribs 31 and 32 and inward projections 33 and 34 with slots 36 and 37. Additionally, the push button 39 is prevented from rotating relative to the plunger by the engagement of one or more protruberances 67 with outwardly turned ears 68 at the top of the plunger. While not all of the ears are engaged by protuberances in the illustrated instrument, a plurality of symmetrically oriented ears are provided to simplify assembly.

Accordingly, the rotation of the push button also rotates the plunger, the tubular detent member and the detent adjusting member, the latter being thereby adjusted axially by threads 28. Assuming that threads 28 are right hand threads, the rotation of the push button in the direction indicated by the mark FIRM will cause the detent adjusting member to move toward the connector to decrease and finally eliminate the resiliency of the tip, while rotating the push button in the opposite direction as indicated by the mark SOFT will move the detent adjusting member toward and ultimately into con tact with the stop member, to increase the resiliency of the tip.

FIG. 9 illustrates an alternative embodiment of the invention employing a substantially identical projectionretraction mechanism but having a different mechanism for varying the resiliency of the writing tip. Since the only substantial differences between this embodiment and that shown in FIG. I reside entirely in the substitution of detent element 71, connector element 72 and spring 73 for tubular detent member 26, detent adjusting member 27, connector member 29 and spring 46, and since these substitutions do not change the basic mode of operation of the propel-repel mechanism as such, the remaining elements are identified by the same numbers used in connection therewith in the other figures, followed by the letter a, and are not described further.

In this construction, detent ribs 31a and the oppositely disposed detent rib, not shown, corresponding to rib 32, are provided on the inner surface of detent element 71, which is axially and rotatably movable within rear section 14a. Element 71 is provided at its forward portion with a helical undulate cam surface 74, which is urged into engagement with a cam finger 75, forming an immovable part of connector element 72, by a spring 73 compressed between a shoulder 76 on element 71 and the lower end 66a of stop member 43a. The detent element, plunger and push button are rotatable together but are prevented from rotating relative to one another in the same manner previously described by means of protuberance 67a, ears 68a, slot 36a, and rib 31a and correspondingly oppositely disposed structures not shown in FIG. 9.

As illustrated in the drawing, the push button has been rotated as far as possible in the direction indicated by the mark SOFT, further rotation in this direction being prevented by the engagements of the stationary cam finger with edge surface 77 of detent element 71. In this condition, the cam finger is in engagement with the rearwardmost undulation of cam surface 74, thereby positioning the detent element in its forwardmost position in which spring 73 is least compressed, to provide a maximum degree of resiliency to the writing point. When the push button is turned in the direction indicated by the mark FIRM, the detent member is rotated relative to the cam finger and is moved rearwardly by virtue of the helical cam surface to increase the compression of spring 73 and ultimately to fully compress the spring to completely eliminate the resiliency of the writing tip. The undulating form of cam surface 74 is provided to define discrete adjustment steps, which might be indicated by a dial associated with the push button, and to minimize the possibility of accidental rotation of the push button when it is used for projecting or retracting the writing unit.

Unlike the previously described embodiment, this structure causes the normal position of the extended writing tip to vary in accordance with the setting of the adjustable resiliency mechanism, for which reason the writing tip must project beyond the end of the housing in its ex tended position by a sufficient distance to compensate for this variation. Additionally, the retracting spring, not shown, corresponding to spring 22 shown in FIG. 1 is modified to compensate for the variable distance between the two extreme positions of the writing unit relative to the housing.

Although the embodiments described above utilize the projection-retraction button as a means also for adjusting the resiliency of the writing unit, it is obvious that a member other than the push button could be employed for this purpose, for example, in the case of a cap actuated or clip actuated pen having no push button. Additionally, it is obvious also that the invention is applicable to pens having projection-retraction mechanisms other than those employing an axially and rotatably movable ratchet member. Since these and other modifications are possible without departing from the spirit of the invention, the foregoing specification is to be considered as illustrative only, the scope of the invention being defined by the following claims.

We claim:

1. A retractile type writing instrument comprising a tubular outer barrel open at its forward end, a writing unit provided with a writing tip, said writing unit being housed within said barrel for movement between a projected position in which said writing tip projects through the open end of said barrel and a retracted position in which said writing tip is withdrawn into said barrel, a slidable member axially movable in said barrel between a first position and a second position more remote from said forward end than said first position, said slidable member being in moving engagement with said writing unit whereby the movement of said slidable member to said first position moves said writing unit to said projected position, a movable detent member for releasably retaining said slidable member in said first position, and resilient means urging said movable detent member toward the open end of said barrel whereby said movable detent member and said writing unit retained thereby are yieldable in a rearward direction when rearward pressure is applied to said writing tip in said projected position.

2. A writing instrument according to claim it including means for adjusting the resilency of said resilent means.

3. In a writing instrument of the type comprising a housing having an open end, a writing unit including a writing tip, said writing unit being mounted movably in said housing for movement between a projected position in which the tip extends through and beyond the open end of said housing and a retracted position in which the tip is withdrawn into said housing, actuating means for moving said unit between said positions, retaining means for retaining said unit in said projected position and means for disabling said retaining means to allow said unit to move to said retracted position, the improvement comprising; means for supporting said retaining means movably within said housing and resilient means urging said retaining means toward the open end of said housing, said retaining means being yieldable against the influence of said resilient means away from the open end of said housing in response to the application of pressure to said writing tip.

4. In a writing instrument of the type comprising a tubular housing open at one end, a writing unit provided with a writing tip, said writing unit being supported in said housing for movement between a projected position in which said writing tip projects beyond the open end of said housing and a retracted position in which said tip is withdrawn into said housing, a spring adapted to urge said writing unit from its projected position to its retracted position, an axially displaceable and rotatable element operatively associated with said writing unit, a detent member adapted to support said element against the influence of said spring in a position corresponding to said projected position when said element is rotationally oriented to a first position relative to said detent member and to allow said unit to be moved by said spring to said retracted position when said element is rotationally oriented to a second position relative to said detent member and actuating means for moving said element axially and alternately to said first and second positions of rotational orientation, the improvement comprising; support means mounting said detent member for axial movement within said housing, stop means limiting the forward movement of said detent means in said housing, and resilient means urging said detent means toward said stop means.

5. A construction according to claim 4 including means defining a rearward facing surface on said detent member, and a spring support member behind said rearward facing surface, said resilient means comprising a coil spring compressed between said rearward facing surface and said spring support member.

6. A construction according to claim 5 including means for moving said spring support member axially of said housing to vary the compression of the coil spring sup- 7 ported between said support member and said rearward facing surface.

7, A construction according to claim 6 in which said means for moving said spring support member axially of said housing comprises cooperating surfaces fixed to said spring support member and to said housing respectively, said cooperating surfaces defining an inclined plane by means of which the axial position of said spring support member corresponds to its mode of rotational orientation relative to said housing.

8. A construction according to claim '7 including an external push button extending beyond the end of said housing opposite said writing tip and supported for axial and rotational movement relative to said housing, means rotatably connecting said push button to said actuating means, and means rotatably connecting said actuating means to said spring support member whereby the rotation of said push button relative to said housing effects the axial adjustment of said spring support member.

9. A writing instrument comprising a barrel open at its opposite ends, a writing unit slidably mounted in said barreltand having a writing point at its forward end adapted to be projected and retracted through the forward end of the barrel, spring means constantly urging said unit toward a retracted position wherein the writing point is concealed Within the barrel, a push button having a portion projecting through the rear end of said barrel and mounted for axial and rotational movement with respect thereto, at least two forwardly directed teeth rotatably and axially movable by said push button, a rotatably and axially movable ratchet member engaged by said writing unit and interposed between said spring means and said teeth, said ratchet member and said teeth having cooperating inclined surfaces such that the force of the engagement of said teeth with said ratchet member when said push button is depressed rotatably biases said ratchet member, a movable detent member encircling said ratchet member, said ratchet member and said movable detent member being formed with coacting members comprising at least one detent lug and a continuous cam,

said cam having longitudinally extending channels separated by pairs of teeth, said teeth defining therebetween a rearwardly inclined surface terminating in a stop surface at a position offset from but intermediate the length of said channels, said lug extending into and being slidable in the channels of said continuous cam and engageable with the teeth thereof, said ratchet member being reciprocable by means of said forwardly directed teeth moved by said push button and rotatable by said forwardly directed teeth when depression of the push button removes said lug from within said channels whereby said lug is positioned between the two teeth of a pair of teeth of said continuous cam so that said spring means can force said lug and stop surface into inter-engagement when said push button is released, means defining an abutment surface adapted to engage said detent member to limit the forward movement thereof, a detent adjusting member including a forwardly facing spring support surface, thread means connecting said detent adjusting member to a stationary member immovably fixed to said housing, a coil spring compressed between said spring support surface and a rearward surface of said detent member, and means for maintaining the rotational orientation of said detent member, said detent adjusting member, said forwardly directed teeth and said push button, whereby the rotation of said push button moves said detent adjusting member axially of said housing by virtue of said thread means to vary the compression of said coil spring.

References Cited by the Examiner UNITED STATES PATENTS 2,946,311 7/1960 Craig 120-42.03 3,065,732 11/1962 Fejes 12042.4 X 3,205,865 9/1965 Lammers 12042.03

FOREIGN PATENTS 875,820 8/1961 Great Britain.

EUGENE R. CAPOZIO, Primary Examiner. HERBERT F. ROSS, Examiner. 

3. IN A WRITING INSTRUMENT OF THE TYPE COMPRISING A HOUSING HAVING AN OPEN END, A WRITING UNIT INCLUDING A WRITING TIP, SAID WRITING UNIT BEING MOUNTED MOVABLY IN SAID HOUSING FOR MOVEMENT BETWEEN A PROJECTED POSITION IN WHICH THE TIP EXTENDS THROUGH AND BEYOND THE OPEN END OF SAID HOUSING AND A RETRACTED POSITION IN WHICH THE TIP IS WITHDRAWN INTO SAID HOUSING, ACTUATING MEANS FOR MOVING SAID UNIT BETWEEN SAID POSITIONS, RETAINING MEANS FOR RETAINING SAID UNIT IN SAID PROJECTED POSITION AND MEANS FOR DISABLING SAID RETAINING MEANS TO ALLOW SAID UNIT TO MOVE TO SAID RETRACTED POSITION, THE IMPROVEMENT COMPRISING; MEANS FOR SUPPORTING SAID RETAINING MEANS MOVABLY WITHIN SAID HOUSING AND RESILIENT MEANS URGING SAID RETAINING MEANS TOWARD THE OPEN END OF SAID HOUSING, SID RETAINING MEANS BEING YIELDABLE AGAINST THE INFLUENCE OF SAID RESILIENT MEANS AWAY FROM THE OPEN END OF SAID HOUSING IN RESPONSE TO THE APPLICATION OF PRESSURE TO SAID WRITING TIP. 